The overall goal of this project is to analyze the autoimmune response to the acetylcholine receptor (ACHR) in myasthenia gravis (MG) and its experimental model, experimental autoimmune myasthenia gravis (EAMG), and to manipulate the expression of the autoantibodies. This analysis will provide the groundwork for the development of antigen-specific, or idiotope (Id)-specific, treatments of MG (and other autoimmune diseases as well) that will be more effective and less toxic than presently available therapies. A systematic survey of both the T cell and B cell immunogenic epitopes of the entire AChR in EAMG-susceptible and EAMG-resistant strains of mice in order to determine the role of the T cell repertoire in the diversity of the antibody response will be carried out. The T cell receptor (TcR) V region gene segment usage from T cell clones directed against the immunogenic T cell epitopes will be determined serologically and by sequencing cDNA or genomic DNA from these cell clones. The latter studies will determine whether the restricted TcR gene segment usage observed in the T-cell-mediated autoimmune disease, experimental allergic encephalomyelitis, also occurs in the antibody-mediated, T-cell-controlled autoimmune response in EAMG. Moreover, the effectiveness in blocking EAMG of anti-clonotypic responses against important TcRs will be assessed. Also, the role of T cells in the protection from EAMG induced by injection of, previously developed, anti-Id monoclonal antibodies will be analyzed. These studies will involve adoptive transfer of T cells from protected animals to naive animals and determination of TcR gene segment usage in the protected animals. The proposed experiments will primarily make use of the pepscanning procedure to survey the AChR epitopes for T cell and B cell immunogenicity, development of T cell clones and hybridomas, amplification of cDNA and genomic DNA by polymerase chain reaction, and direct sequencing of amplified products to determine TcR gene segment usage.